During production of paper or board products there is often a desire to add nanoparticles either to the furnish of the paper or board or to the surface of the formed paper or board product. The nanoparticles are often added in order to reduce production cost and/or in order to improve the properties, such as printing properties, of the finished paper or board product.
Nanoparticles are also used in many other applications, such as production of composites in which the nanoparticles often is added in order to reduce the weight and increase elastic modulus of the composites.
The problem when working with dispersions or slurries comprising nanoparticles is that they are not stable and the nanoparticles easily form aggregates which not as reactive as nanoparticles in free form. Furthermore, dispersions comprising nanomaterial often have a problem with dusting and it could also be hazardous to handle the dispersions comprising nanoparticles since they e.g. are being adsorbed by the skin. Dried dispersions comprising microfibrillated cellulose often also has problems with dusting.
There is thus a need for an improved process for producing a stable dispersion comprising nanoparticles with improved properties.